diff --git a/source/snes9x/memmap.cpp b/source/snes9x/memmap.cpp
index c835e80..7714bef 100644
--- a/source/snes9x/memmap.cpp
+++ b/source/snes9x/memmap.cpp
@@ -3239,6 +3239,8 @@ void CMemory::Map_SPC7110HiROMMap (void)
 	map_index(0x00, 0x00, 0x6000, 0x7fff, MAP_HIROM_SRAM, MAP_TYPE_RAM);
 	map_hirom(0x00, 0x0f, 0x8000, 0xffff, CalculatedSize);	
 	map_index(0x30, 0x30, 0x6000, 0x7fff, MAP_HIROM_SRAM, MAP_TYPE_RAM);
+	if(Memory.ROMSize >= 13)
+		map_hirom_offset(0x40, 0x4f, 0x0000, 0xffff, CalculatedSize, 0x600000);
 	map_index(0x50, 0x50, 0x0000, 0xffff, MAP_SPC7110_DRAM, MAP_TYPE_ROM);
 	map_hirom(0x80, 0x8f, 0x8000, 0xffff, CalculatedSize);
 	map_hirom_offset(0xc0, 0xcf, 0x0000, 0xffff, CalculatedSize, 0);
diff --git a/source/snes9x/spc7110dec.cpp b/source/snes9x/spc7110dec.cpp
index 65d5586..6cc2867 100644
--- a/source/snes9x/spc7110dec.cpp
+++ b/source/snes9x/spc7110dec.cpp
@@ -42,7 +42,7 @@ void SPC7110Decomp::write(uint8 data) {
 }
 
 uint8 SPC7110Decomp::dataread() {
-  unsigned size = memory_cartrom_size() - 0x100000;
+  unsigned size = memory_cartrom_size() > 0x500000 ? memory_cartrom_size() - 0x200000 : memory_cartrom_size() - 0x100000;
   while(decomp_offset >= size) decomp_offset -= size;
   return memory_cartrom_read(0x100000 + decomp_offset++);
 }
diff --git a/source/snes9x/spc7110emu.cpp b/source/snes9x/spc7110emu.cpp
index 69b3e7d..8ce99b8 100644
--- a/source/snes9x/spc7110emu.cpp
+++ b/source/snes9x/spc7110emu.cpp
@@ -91,7 +91,7 @@ void SPC7110::reset() {
 }
 
 unsigned SPC7110::datarom_addr(unsigned addr) {
-  unsigned size = memory_cartrom_size() - 0x100000;
+  unsigned size = memory_cartrom_size() > 0x500000 ? memory_cartrom_size() - 0x200000 : memory_cartrom_size() - 0x100000;
   while(addr >= size) addr -= size;
   return addr + 0x100000;
 }